RM0319 datasheet(147/368 Pages) STMICROELECTRONICS

147 / 368 page

RM0319

Fast Ethernet port (MII0)

Doc ID 022640 Rev 3

147/368

[20]

TCH

When set, this bit indicates that the second address in the descriptor is the

Next Descriptor address rather than the second buffer address. When

TDES0[20] is set, TBS2 (TDES1[28:16]) is a "don't care" value.

TDES0[21] takes precedence over TDES0[20].

[19:18]

Reserved

[17]

TTSS

Transmit Time Stamp Status. This field is used as a status bit to indicated

that a time stamp was captured for the described transmit frame. When this

bit is set, TDES2 and TDES3 have a time stamp value captured for the

transmit frame. This field is only valid when the descriptor’s Last Segment

Control bit (TDES0[29]) is set.

[16]

IHE

IP Header Error. When set, this bit indicates that the MAC transmitter

detected an error in the IP datagram header. The transmitter checks the

header length in the IPv4 packet against the number of header bytes

received from the application and indicates an error status if there is a

mismatch. For IPV6 frames, a header error is reported if the main header

length is not 40 bytes. Furthermore, the Ethernet Length/Type field value for

an IPv4 or IPv6 frame must match the IP header version received with the

packet. For IP4 frames, an error status is also indicated if the Header Length

field has a value less than 0x5.

[15]

Error Summary. It is the logical OR of the following bits of this descriptor. [1],

[2], [8], [9], [10], [11], [13] and [14].

[14]

Jabber Timeout. If set, it indicates that the MAC transmitter has experienced

a jabber timeout.

[13]

Frame Flushed. If set, it indicates that the DMA flushed the frame due to a

software flush command given by the CPU.

[12]

IPE

IP Payload Error When set, this bit indicates that MAC transmitter detected

[11]

Loss of Carrier. If set, it indicates that loss of carrier occured during frame

transmission. This is valid only for the frames transmitted without collision

when the MAC operates in Half-Duplex mode.

[10]

No Carrier. If set, it indicates that the carrier sense signal

[09]

Late Collision. If set, it indicates that the frame transmission was aborted due

to a collision after the collision window. This bit is not valid if the UnderFlow

Error bit is set.

[08]

Excessive Collision. If set, it indicates that the frame transmission was

aborted after 16 successive collisions while attempting to transmit the

current frame.

Note: if the DR (Disable Retry) bit in the MAC Configuration register

(Register 0) is set, the EC bit is set after the first collision and the

transmission is aborted.

[07]

VLAN Frame. If set, it indicates that the transmitted frame was a VLAN-type

frame.

[06:03]

Collision Count. This 4 bit counter value reports the number of collisions

occuring before the frame was transmitted.

Note: The count is not valid when the EC bit (TDES0[8]) is set.

Table 44.

Transmit descriptor 0 (TDES0) (continued)

Bit

Name

Description

RM0319 датащи(PDF) 147 Page - STMicroelectronics

RM0319 датащи(HTML) 147 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL